Rufus g



(No Model.)

R. G. STANBROUGH.

ARTIFICIAL TOOTH.

No. 468,922. Patented Feb. 16, 1892.

UNITED STATES PATENT OEEICE.v

RUFUS G. S'IANBROUGII, OF NEW YORK, N. Y., ASSIGNOR TO AROBERT SEAMAN,OF SAME PLACE.

ARTIFICIAL TEETH.

SPECIFICATION forming part of Letters Patent No. 468,922, dated February16, 1892.

I Application tiled December 9, 1891l Serial No. 414,513. (No model.)

To @ZZ whom it may concern.-

Be it known that I, RUFUs G. STANBROUGH, a citizen of the United States,and a resident of New York, in the county of New York and State of NewYork, have invented certain new and useful Improvements in ArtificialCrowns for Teeth, of which the following is a specification.

My invention relates to that class of dental surgery in which what istechnically known as an artificial denture is secured to the naturalportion of a tooth.

Practically the object ot' my invention is to make the joint betweensuch artificial denture, commonly called a crown, and the natural-toothportion or root firm, smooth, and durable, and a further Objectis toaccomplish this result expeditiously and in an artistic, economical, andreliable manner.

In the accompanying drawings, in the several figures of which like partsare designated by similar letters of reference, Figures l, 2, 3, 4, 5,6, 7, and 8 illustratethe various steps or operations by which the rootor natural portion of the tooth is shaped and prepared to receive theartificial cap or crown. Fig. 9 is a cross-section of the artificial capor crown; Fig. 10, a cross-section of the shaped and prepared naturalportion or root of the tooth with the artificial cap or crown inposition. Fig.

1l is an outline view, in side elevation,'of the artificial dentureattached to the natural portion of the tooth.

In carrying out my invention the natural portion or root A of the toothis first prepared to receive the artificial cap or crown in thefollowing manner: I first remove the uneven portions of the naturaltooth by filling, grinding, or burring it to a condition of regularityand exposing thel natural pulp-canal from which the pulp has beenremoved and the canal properly treated. I then enlarge the canal,forming a hole or cavity G therein by means of a drill H,Fig.1,following as nearly as possiblein the line of the direction C, throughwhich the nerve and blood-vessels normally enter. After this hole orcavity G has been formed I employ a rose-reamer I, having a stem J,Fig.v2, and smooth off the irregulari` ties upon the outer or free endor natural portion of the root A. The stem J of this rosereamer I is ofsubstantially the same diameter as the cavity G, so that it will act asa guideto the reamer during the operation of grinding or cutting awaythe irregular portion of the natural portion of the tooth to be treated.I then proceed to form on each side of the cavity G btwo smallercavities M M. For this purpose I employ a specially-constructed cuttingdevice for the drills, which consists of a circular plate D, having twoopenings therein E E provided with a stem Fof the same diameter, orsubstantially so, as the cavity G. This stem F is inserted in the cavityG and the plate D brought to bear against the free end of the naturalportion of the tooth. I then employ a drill or drills K, which areoperated to form in the root end or natural portion of the tooth A theholes or cavities M M. These smaller cavities are formed as closely aspossible to the walls of the larger cavity G. After one of the smallercavities has been formed-for instance M- I remove the drill and insert asteady-pinl L to hold the guiding device in place during the operationof forming the other cavity for instance, M. As a result of theseoperations, the root is now prov-idedwith a central cavity G and the twoshort cavities 'M M', (see Fig. 4,) respectively arranged closeltof thewalls of the cavity G. I now employ the rose-reamer N, having a stem Oof suitable dimensions to fit in the cavity lG, and by means of thisreamer I cut away the walls between the cavity G and the cavities M M',thus forming at the outer extremity of the cavity G a cavity of theshape and cross-section shown at P in Fig. 5. I next by means of a tap Qscrew-thread the cavity G, as shown in Fig. 5. I then form a trueconcave groove R in the root end by means of the mechanism shown in Fig.G, which consists of burring or cutting mechanism comprising revolvingburrs or cutters V V, supported upon a shaft arranged in a suitable frame and adapted to shape the root end, as may be desirable. Theparticular mechanism which I prefer to employ for this purpose isdescribed in a concurrent application for` Letters Patent, and thismechanism, broadly stated, consists, es-

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` cured therein a tube Y, of suitable material sentially, of a guide orholder supported on the frame of the cutting-tool and arranged toenter-and adjust itself in cavities formed in the root end, whereby asthe bu rrs or cutters operate they will be firmly held and continuouslybear in a given direction to me-A chanically shape the root end. Theguiding and cutting mechanism for this purpose which I prefer to employconsists of revolving burrs orcutters V V, carried on the shaft V',supported in a frame V2. The lower portions of this frame are providedwith square grooves Vs and an extension V4, which is also grooved inline with the grooves V3. The guiding device of this mechanism comprisesa bifurcated frame V5, which straddles the shaft, its lower portionsentering the grooves V4 and extensions of said grooves and beingexteriorly screw-threaded to engage a thumb-nut V, by means of which thetwo legs of the bifurcated :frame V5 are rigidly held in position in theframe V2. The principal portion of this bifurcated frame V5 is providedwith a `projecting stein S, having arranged at its base a holder,technically called a-templet, which consists of a substantially circularcentral portion U, terminating in two semicircular lugs T T,diametrically arranged with relation to each other. The stem S is ofsuitable dimensions to enter and snugly t in the cavity G in the rootend, and the lugs T T are of suitable dimensions to enter and snugly itin the cavity P. This templet or guide being properly inserted, asdescribed, in the root end', and the burrs brought to bear against theouter end thereofthe operation of grinding or cutting away the root endso as to give it the proper shape-such, forinstance, as the concavegroove R-is proceededwith. It will be observed that the templetpositively directs the cutting mechanism, so that a true groove or shapemay be given to the root end. This groove may be formed in any desireddirection by adjusting the templet and thus regulating the cuttingaction of the burrs. I next take a screw-.threaded pin NV, of snitablediameter and length, and screw it into the screw-threadedhole G, asshown in Fig. 7.

The artificial crown or cap B, which may be of any suitable shape *andlof any suitable material, has placed into and properly seand shape. (SeeFigs. 8, 9, and l0.) This tube projects above the top of the crown B adistance equal to the depth of the cavity P,'

. ner: I take a small sheet X of some iexible substance-such, forinstance, as metal foil-4 and press it tightly against the free end ofthe root A, as shown in Fig. 8. This sheet X is then removed and trimmedto the shape of l the root as indented upon it and is then laid upon theupper surface of the crown B, which may be thereupon tiled down and cutaway or shaped to the exact contour of the sheet in any convenientmanner. After the crown .B has been properly shaped, as described, itmay be attached to the root A by cementing the parts together. After thecrown B has been properly shaped and is ready for attachment to the rootA in the manner described I prefer to employ a suitable material to filland hermetically seal any interstices between the parts.

It is obvious that in the manner stated an artificial denture may beattached to the natural portion or root mechanically and rapidly andwill be firmly and immovably iiXed in place and atv the same time havethe appearance and answer all the purposes of a natural tooth. It isalso obvious that my invention may be employedwith 'what is technicallytermed a bridge-that is to say, a device connecting two non-adjacentteeth between which a tooth or teeth are missingthe said bridge actingas a device to receive the artificial dentures, as hereinabovedescribed. Vhat I claim as my invention, and desire to secure by LettersPatent, is

l. The herein-described process of attaching ar'tilicial crowns to thenatural-.tooth portions or roots, which consists in first forming acentral cavity in the root, reaming out the natural pulp-canal, theninserting the drillguide in said cavity and drilling smaller diametriccavities parallel to said central cavity, then removing the wallsbetween the said central cavity and the diametric cavities, thusenlarging at the free end of the root the centrai cavity and-givingthesame the shape of a central circular orilice having diametricarc-shaped openings, then screw-threading the central cavity, thencurving the free end of the root by a burring mechanism engaging andholding accurately in position in the central cavity and the enlargedendthereof, then insertingathreaded pin or post in the threaded centralcavity, and finally inserting the projecting end of the said threadedpin or post in an artificial crown shaped to tit the root end and firmlyuniting the same by cement, substantially as described. j

2.1An artificial tooth-crown having its top curved and provided with atube secured in the body of said crown, but not extending through thesame, said tube projecting from the top of the crown to engage and besecured in the root end, substantially as described.

Signed at New York, in the county of New York and State of New York,this 22d day of December, A. D. 1890.

RUFUS Gr. STANBROUGII.

Witnesses:

E. R. KNowLEs, E. IRVING CARR.

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